Dear SSL-Community,

RoboCup 2023 will start in 3 weeks, so we wanted to give you some updates regarding playing with walls and the grouping.

Playing with walls

This year, we will offer all teams to play their matches with walls.

To allow for some preparation, the preference to play with walls can not be changed arbitrarily: We ask all teams to announce their preference till June 23rd (anywhere on earth)through this form https://forms.gle/eeWT9Z8FQBJVaTmH6. The responses are published https://docs.google.com/forms/d/1Kb2voTSFtIJvoxmoRSsCpZO-80mZgIoPBiBJQQCohjA/viewanalyticsimmediately. The preference is binding for all matches in the group phase. It can be changed once between the group and the elimination phase through this form https://forms.gle/oNAEMGAjE77TcSCH8and is then binding for the remaining games.

A match is played with walls, if both teams have announced their preference for wall games.

Playing with walls underlies the following rule changes:

*

Rule 6 - Ball Leaves The Field https://robocup-ssl.github.io/ssl-rules/sslrules.html#_ball_leaves_the_fielddoes not apply

*

The field size is increase by the field boundary - ssl-vision will send a Geometry with adjusted field sizes and a boundary width of zero

Tournament Structure & Group seeding

We have finished the schedule and the seeding for the upcoming Robocup. You can find the schedule at https://docs.google.com/spreadsheets/d/1EUjOuGdRLxptcESywCAKdruRATmy2j6ezu6D... https://docs.google.com/spreadsheets/d/1EUjOuGdRLxptcESywCAKdruRATmy2j6ezu6DLRCiWlo/edit#gid=0.

Division A will play a 8 player competition, with 2 groups of 4 teams each,

followed by a double-elimination knockout tournament, similar to the competition in 2019.

Compared to 2019, the matches of 'winner of each group against 4th of the other group' are canceled,

and the winner of the group is assumed to win this, and the last place of the group is assumed to lose that match.

As a result, 1st of each group skips Upper Round 1 / 2 (which now only 2nd vs 3rd each) and starts in the upper semifinals.

The 4th of each group starts in the Lower Tournament.

Division B will play a 12 player competition, with 4 groups of 3 teams each,

followed by a single-elimination knockout tournament. Similar to 2019 and LARC 2022, but different to Robocup 2022 in Bangkok.

This also means 90 mins per match in Division B (was 120 mins). This is necessary to accommodate the increased number of participants.

Please be prepared that the schedule is going to be tight.

As in Division A, the winners of each group get to skip the first round of the knockout stage as a reward for winning their groups.

The Repositoryhttps://github.com/RoboCup-SSL/ssl-grouping https://github.com/RoboCup-SSL/ssl-groupingis already updated to include the newly seeded teams.

As we are going to draw both a two group and a four group competition,

I modified the software to first take the number of groups as a first parameter, followed by the two random seeds.

We also disabled country locking in Division A (too few distinct countries participating),

but enabled it in Division B except for Brazil. So if you're competing in Division B and are from a different country than Brazil,

you are promised not to play another team from your country in the group stage.

We are going to use the random numbers given by the following link:

https://www.random.org/integers/?num=6&min=1&max=123456&col=5&am... https://www.random.org/integers/?num=6&min=1&max=123456&col=5&base=10&format=plain&rnd=date.2023-06-24

Please note that this link does not work yet (to make sure I didn't pick some random numbers I liked best),

because it will use the pre-generated random numbers from 24th of June and will only work on and after 24th of June.

As soon as the numbers are available, the link will create 6 numbers. The two most left numbers are going to be used

to draw the division A groups (with `ln -f teamsA.txt teams.txt; ./grouping 2 <firstSeed> <secondSeed>`)

and the second pair to draw the division B groups (with `ln -f teamsA.txt teams.txt; ./grouping 4 <thirdSeed> <fourthSeed>`).

TC/OC has been made aware that both teams from China are currently experiencing visa issues for France. To avoid the issue where the top seed from one of the two divA groups is missing (and the group is as a result much weaker) the third pair will be used to draw groups where ZJU is replaced by a dummy team (in seed 3), ER-Force is moving up to pool 1, and KIKs is moving up to pool 2.

If you want to challenge the seeding for the competition, you have to do this before the groups are drawn, i.e. before random.org published the random numbers for the 24th.

As the earth is round and time zones are unpredictable, send your complaints on or before 22nd AoE. See you in France!